More powerful smokeless powder allowed the use of smaller, non-heeled projectiles in existing caliber guns.
The heeled bullet design has many advantages, mainly when coupled with the straight or slightly tapered walled cases it appeared in.
For pistols, converting a cap and ball revolver to use cartridges was as simple as cutting off part of the rear of the cylinder, replacing it with a frame-mounted ring, and changing the hammer.
It also made new revolvers easier and cheaper to manufacture, as the chambers could simply be drilled straight through the cylinder, whereas bullets narrower than the case required two different diameters to be drilled, and careful control of the depth for the larger diameter bit.
[6] This prevents the lubricant, usually a grease or wax, from picking up dirt and grit which can damage the bore.
The recent rise in popularity of Cowboy Action Shooting has increased interest in these old cartridges, and there are even a few new replica firearms being made to chamber them.